A1 - The pink arrows (images 1 and 2; 6 and 7) demonstrate a | Figure 1

Pomeranz

Radiology

A1 - The pink arrows (images 1 and 2; 6 and 7) demonstrate a tail extending back to the joint capsule and subsheath portion of the extensor carpi ulnaris.

A2 - (a) ganglion pseudocyst, (b) epidermoid, (c) myxoma, (d) capsular cyst, (e) pisotriquetral bursal cyst, or (f) capsulosynovial cyst associated with inflammatory arthritis (such as rheumatoid).

A3 - (a) ganglion with a tail to either the capsule or sheath of a tendon, (b) neural tumor with a tail to a nerve, (c) aneurysm or pseudoaneurysm with a tail to a vessel, or (d) capsular or synovial cyst with a tail to a joint.

A4 - The most common is along the dorsal scapholunate interval near the dorsal limb of the scapholunate ligament (SL) and the radial limb of the intercarpal ligament. Sometimes these project at the junction of the scaphoid and base of the capitate dorsally.

The second most common location is along the palmar aspect of the wrist near the volar SL ligament and capsule near the base of the radioscaphocapitate extrinsic or the base of the radial lunatotriquetral ligament extrinsic.

In other words, a ganglion in this location is extremely atypical. Its intimacy with the extensor carpi ulnaris is problematic as it relates to dynamic motion (i.e. can restrict).

Why you should join Figure 1

Axial (image 1) and sagittal (image 2) T2 MRI of the wrist show a ganglion cyst (arrow) arising from the dorsal surface of the wrist. Ganglion cysts represent the most common mass of the hand. They most commonly occur along the dorsal aspect of the wrist. The cysts are usually asymptomatic. Patients typically present to their doctor because they feel a firm, well circumscribed, painless mass. On exam, the ganglion cyst is usually fixed to deep structures but not the skin.

Lateral radiograph (image 1) of the hindfoot and midfoot shows an oval-shaped soft tissue mass (arrow) superior to the navicular and medial cuneiform. On the T2-weighted sagittal MRI (image 2) this mass is confirmed to represent a ganglion cyst. Ganglion cysts may occur as a result of trauma or degeneration. They most commonly occur along the dorsum of the wrist. However, approximately 10% occur in the foot. While most patients present with an asymptomatic soft tissue mass, ganglions cysts of the foot can be painful due to their locations near the dorsalis pedis artery and the medial branch of the deep peroneal nerve as well as the potential for shoes to aggravate the cyst.

This 44-year-old female presents with right wrist pain. You are shown five images. A coronal proton density (image 1), a coronal proton density fat suppression (image 2), two sagittal proton density fat suppression (images 3 and 4), and an axial or short-axis proton density (image 5). A hyperintense mass around the ulna is obvious.

Intraoperative photographs outlining the steps of a dorsal approach to the distal radius in a right wrist. (A) A dorsal incision is drawn centered slightly radially over the axis of the radius. The oblique line marks the distal radius articular surface as defined by fluoroscopy. (B) The retinaculum over the third dorsal compartment has been opened, exposing the extensor pollicis longus (EPL) tendon. (C) The EPL is retracted radially. Distally, a retractor has been placed between the second (extensor carpi radialis brevis) and the fourth (extensor digitorum communis) extensor compartment tendons to expose the dorsal wrist capsule. (D) Subperiosteal dissection exposes the distal radius and the proximal carpal row. Note that the fourth dorsal compartment subsheath has not been violated. (E) After reduction, the retinaculum is anatomically repaired, leaving the EPL dorsally in a protected position.